One conventional technology for displaying a stereoscopic image is to prepare an image for the right eye (hereinafter “right-eye image”) and an image for the left eye (hereinafter “left-eye image”), and then present the right-eye image and the left-eye image only to the right eye and the left eye, respectively. Here, the right-eye image and the left-eye image represent the fields of view of the right eye and the left eye, respectively. Such technology for displaying a stereoscopic image enables the user to experience 3D due to parallax, i.e., the amount of horizontal displacement between the right-eye image and the left-eye image, and is used in movies and the like to make objects look stereoscopic. With the dissemination of such technology, devices for editing captured stereoscopic images are expected to be used at home in the future.
In image editing, an image of a pointer (hereinafter “pointer image”) may be displayed on a screen together with a stereoscopic image for the purpose of, for example, specifying an object in the stereoscopic image or specifying a display area. At this time, in order to enable more accurate pointing of an object, it is possible to display a pointer image in a stereoscopic manner by creating two pointer images with parallax, and composite the stereoscopic pointer image with the stereoscopic image. Here, if (i) the display depth of the stereoscopic pointer image is fixed and (ii) the display depth of an object pointed by the stereoscopic pointer image is different from the fixed display depth of the stereoscopic pointer image, the following visibility problem arises: the user sees double vision of the stereoscopic pointer image when focusing his/her eyes on the object, and double vision of the object when focusing his/her eyes on the stereoscopic pointer image. In view of the above problem, Patent Literature 1 discloses technology for correcting the display depth of a stereoscopic pointer image to match the display depth of an object pointed by the stereoscopic pointer image. The technology disclosed in Patent Literature 1 makes two pointer images that are to be composited with right-eye and left-eye images, respectively, demonstrate parallax in accordance with parallax of the stereoscopic image (i.e., the amount of displacement between the right-eye and left-eye images) at a pointer position to be pointed by the stereoscopic pointer image. As a result, the display depth of the stereoscopic image and the display depth of the stereoscopic pointer image match at the pointer position, and visibility is improved.